The man appointed head of the advisory council for the misuse of drugs once called for ecstasy to be downgraded to a class B drug, politics.co.uk can exclusively reveal.
Professor David Nutt, who replaces Sir Michael Rawlins as chair of the Advisory Council on the Misuse of Drugs (ACMD) this afternoon, made the comments at a science and technology committee hearing in 2006.
"I think the evidence base for classification producing deterrence is not strong and we see that with a number of drugs," he said.
"I think 4MTA, LSD and ecstasy probably shouldn't be class A."
Former chairman Sir Michael Rawlins said: "I welcome the appointment of Professor David Nutt as my successor. I have every confidence that he will provide excellent and innovative leadership to the council providing the best possible advice to government."
Home secretary Jacqui Smith praised Sir Michael Rawlins and said: "I look forward to working with his successor so that the advisory council's expert advice can continue to inform our drive to reduce the harm caused by illegal substances."
There are signs Professor Nutt's appointment is already opening up the issue of ecstasy's classification. A Home Office spokesperson told politics.co.uk: "The ACMD will consider the evidence for the classification of ecstasy with an open mind based upon its social misuse and harms relative to other drugs in the classification system."